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Objective: To validate a method using self-reported speech communication effort in noise to estimate occupational noise levels by comparing with measured noise levels. Design: A comparative observational study. Reported vocal effort to communicate with a person at a distance of 1.2 m during workplace-related tasks was used to provide an estimate of noise levels in the workplace. These estimated noise levels were compared against noise level measurements obtained using personal noise dosimetry badges for corresponding tasks undertaken by participants. Study sample: Participants ( n  = 168) aged 16-25 years were recruited from companies where workplace noise levels were at least 85 dB(A). Results: Estimated noise levels using speech communication ability were evenly distributed above and below the measured noise levels ( n  = 134), indicating a lack of systematic bias in the method. For 91% of participants, estimates of noise levels using speech communication were within ±6 dB of the measured levels, whilst 56% were within ±3 dB. Conclusions: Report of speech communication effort required in noise by employees is an effective method of estimating noise levels within the workplace. This can be used for retrospective noise level assessment where there are no recorded noise level measurements, such as for retrospective research studies or in medicolegal work.

Objective: The aim of the present study was to investigate how well the virtual psychophysical measures of spatial hearing from the preliminary auditory profile predict self-reported spatial-hearing abilities., Design: Virtual spatial-hearings tests (conducted unaided, via headphones) and a questionnaire were administered in five centres in Germany, the Netherlands, Sweden, and the UK. Correlations and stepwise linear regression models were calculated among a group of hearing-impaired listeners., Study Sample: Thirty normal-hearing listeners aged 19-39 years, and 72 hearing-impaired listeners aged 22-91 years with a broad range of hearing losses, including asymmetrical and mixed hearing losses., Results: Several significant correlations (between 0.24 and 0.54) were found between results of virtual psychophysical spatial-hearing tests and self-reported localization abilities. Stepwise linear regression analyses showed that the minimum audible angle (MAA) test was a significant predictor for self-reported localization abilities (5% extra explained variance), and the spatial speech reception threshold (SRT) benefit test for self-reported listening to speech in spatial situations (6% extra explained variance)., Conclusions: The MAA test and spatial SRT benefit test are indicative measures of everyday binaural functioning. The binaural SRT benefit test was not found to predict self-reported spatial-hearing abilities.

Objective: This paper describes the composition and international multi-centre evaluation of a battery of tests termed the preliminary auditory profile. It includes measures of loudness perception, listening effort, speech perception, spectral and temporal resolution, spatial hearing, self-reported disability and handicap, and cognition. Clinical applicability and comparability across different centres are investigated., Design: Headphone tests were conducted in five centres divided over four countries. Effects of test-retest, ear, and centre were investigated. Results for normally-hearing (NH) and hearing-impaired (HI) listeners are presented., Study Sample: Thirty NH listeners aged 19-39 years, and 72 HI listeners aged 22-91 years with a broad range of hearing losses were included., Results: Test-retest reliability was generally good and there were very few right/left ear effects. Results of all tests were comparable across centres for NH listeners after baseline correction to account for necessary differences between test materials. For HI listeners, results were comparable across centres for the language-independent tests., Conclusions: The auditory profile forms a clinical test battery that is applicable in four different languages. Even after baseline correction, differences between test materials have to be taken into account when interpreting results of language-dependent tests in HI listeners.

Objective: Established methods for predicting speech recognition in noise require knowledge of clean speech signals, placing limitations on their application. The study evaluates an alternative approach based on characteristics of noisy speech, specifically its sparseness as represented by the statistic kurtosis., Design: Experiments 1 and 2 involved acoustic analysis of vowel-consonant-vowel (VCV) syllables in babble noise, comparing kurtosis, glimpsing areas, and extended speech intelligibility index (ESII) of noisy speech signals with one another and with pre-existing speech recognition scores. Experiment 3 manipulated kurtosis of VCV syllables and investigated effects on speech recognition scores in normal-hearing listeners., Study Sample: Pre-existing speech recognition data for Experiments 1 and 2; seven normal-hearing participants for Experiment 3., Results: Experiments 1 and 2 demonstrated that kurtosis calculated in the time-domain from noisy speech is highly correlated (r > 0.98) with established prediction models: glimpsing and ESII. All three measures predicted speech recognition scores well. The final experiment showed a clear monotonic relationship between speech recognition scores and kurtosis., Conclusions: Speech recognition performance in noise is closely related to the sparseness (kurtosis) of the noisy speech signal, at least for the types of speech and noise used here and for listeners with normal hearing.

Due to individual characteristics such as head size, earmould type, and earmould venting, the directional benefit that an individual will obtain from a hearing aid cannot be predicted from average data. It is therefore desirable to measure real ear directional benefit. This paper demonstrates a method to measure real ear hearing aid directivity based on a general approach to measure the broadband output signal-to-noise ratio of a hearing aid. Errors arising from non-linearity were tested in simulation and found to be low for typical hearing aid compression ratios. Next, the efficacy of the method to estimate directional benefit was demonstrated on KEMAR. Finally the variability of directional benefit was explored in real-ears. Significant differences in signal-to-noise ratio between directional and omnidirectional microphone settings were demonstrated at most azimuths. Articulation-Index-weighted directional benefit varied by more than 7 dB across ears at some azimuths. Such individual variation in directional benefit has implications when fitting hearing aids: it should not be assumed that all users will receive similar directional benefit from the same hearing aid.

A prototype self-report measure of vestibular rehabilitation outcome is described in a previous paper. The objectives of the present work were to identify the most useful items and assess their psychometric properties. Stage 1: One hundred fifty-five participants completed a prototype 36-item Vestibular Rehabilitation Benefit Questionnaire (VRBQ). Statistical analysis demonstrated its subscale structure and identified redundant items. Stage 2: One hundred twenty-four participants completed a refined 22-item VRBQ and three established questionnaires (Dizziness Handicap Inventory, DHI; Vertigo Symptom Scale short form, VSS-sf; Medical Outcomes Study short form 36, SF-36) in a longitudinal study. Statistical analysis revealed four internally consistent subscales of the VRBQ: Dizziness, Anxiety, Motion-Provoked Dizziness, and Quality of Life. Correlations with the DHI, VSS-sf, and SF-36 support the validity of the VRBQ, and effect size estimates suggest that the VRBQ is more responsive than comparable questionnaires. Twenty participants completed the VRBQ twice in a 24-hour period, indicating excellent test-retest reliability. The VRBQ appears to be a concise and psychometrically robust questionnaire that addresses the main aspects of dizziness impact.

Research suggests that Vestibular Rehabilitation (VR) is an effective treatment for dizziness, but there is currently no measure specifically designed to assess treatment outcome. A review of existing self-report measures of dizziness indicates that no measure has been designed for longitudinal application and all suffer from limitations which restrict their usefulness in measuring VR outcome. A need for a psychometrically robust patient-oriented measure of quality of life benefit from VR is identified. The aim of the present study was to explore dimensions relevant to VR with a view to developing a measure of outcome. Eighteen adults receiving VR participated in interviews about the quality of life impact of dizziness. Qualitative analysis revealed 64 themes describing self-perceived quality of life impact. Themes were developed into potential questionnaire items and 35 were selected to represent the quality of life impact of dizziness in a prototype questionnaire. A quarter of items in the prototype questionnaire refer to issues not addressed by existing measures; the remaining items draw together issues covered by the range of questionnaires currently in use.

We performed a retrospective analysis of TEOAEs from 1415 neonatal ears to investigate whether the application of linear averaging techniques may provide greater screening specificity than conventional nonlinear averaging techniques. Pass criteria were based on correlations between replicate averages, and pass rates were compared between linear and nonlinear averaging techniques. The linear averaging technique gave a higher pass rate as hypothesized, so that 35% of ears that passed using the linear method failed using the nonlinear method. In addition, lack of saturation was more evident for the short-latency components of the TEOAE. These results, from a large sample of recordings obtained under field conditions, indicate that there is potential to improve specificity of neonatal TEOAE screening using linear averaging techniques. A combination of linear and nonlinear techniques for the long and short latency components of the TEOAE, respectively, may offer further advantages.

This study investigated learning, in normal-hearing adults, associated with training (i.e. repeated practice) on the discrimination of ongoing interaural time difference (ITD). Specifically, the study addressed an apparent disparity in the conclusions of previous studies, which reported training-induced learning at high frequencies but not at low frequencies. Twenty normal-hearing adults were trained with either low- or high-frequency stimuli, associated with comparable asymptotic thresholds, or served as untrained controls. Overall, trained listeners learnt more than controls and over multiple sessions. The magnitudes and time-courses of learning with the low- and high-frequency stimuli were similar. While this is inconsistent with the conclusion of a previous study with low-frequency ITD, this previous conclusion may not be justified by the results reported. Generalization of learning across frequency was found, although more detailed investigations of stimulus-specific learning are warranted. Overall, the results are consistent with the notion that ongoing ITD processing is functionally uniform across frequency. These results may have implications for clinical populations, such as users of bilateral cochlear implants.

Mobile phone ownership and usage is now widespread and public concern has developed over possible harmful physiological effects of their use. This study aimed to investigate the prevalence of student mobile phone ownership and any possible chronic effects of usage on hearing, tinnitus and balance. Questionnaires for electronic self-completion were distributed to University of Southampton postgraduates, and 117 out of 160 returned met the criteria for analysis. A total of 94% were current mobile phone users, and only 2% had never used a mobile phone. Duration of ownership and daily usage ranged from 0-7 years and 0-45 minutes respectively. Text-messaging was more popular than talking. High or long-term users reported no worse hearing, tinnitus, or balance than low or short-term users. The results of this study confirm that the prevalence of mobile phone ownership amongst students is extremely high. However there appear to be no harmful effects of mobile phone usage on their audiovestibular systems within the range of exposure of the study, insofar as can be detected by the self-report method employed.

The advent of bilateral cochlear implants (CIs) has increased interest in learning on binaural tasks, and studies in normal-hearing listeners provide important background information. However, few studies have considered learning with discrimination of interaural time difference (ITD). Here, learning with ITD was explored using stimuli that are more relevant to bilateral CIs than used previously. Inexperienced listeners were trained with envelope-based ITD using high-frequency amplitude-modulated tones with or without an interaural carrier frequency difference (IFD), the former to simulate asymmetrical bilateral CI insertions. All were tested with and without IFD before and after training. In most listeners, ITD thresholds improved substantially with training, not necessarily reaching asymptote after 3,000 trials. In these, the magnitude and time-course of learning was larger than anticipated from a previous study with low-frequency ITD. Learning generalized across IFD and the effect of IFD on ITD thresholds at post-test was smaller than reported previously. These results have implications for studies of bilateral CIs, such as the need to provide extensive training to avoid over-estimating any apparent 'impairment'.

Methodology is proposed for perceptual assessment of both subjective sound quality and speech recognition in such way that results can be compared between these two aspects. Validation is performed with a noise suppression system applied to hearing instruments. A method termed Interpolated Paired Comparison Rating (IPCR) was developed for time efficient assessment of subjective impression of different aspects of sound quality for a variety of noise conditions. The method is based on paired comparisons between processed and unprocessed stimuli, and the results are expressed as the difference in signal-to-noise ratio (dB) between these that give equal subjective impression. For tests of speech recognition in noise, validated adaptive test methods can be used that give results in terms of speech-to-noise ratio. The methodology was shown to be sensitive enough to detect significant mean differences between processed and unprocessed speech in noise, both regarding subjective sound quality and speech recognition ability in groups consisting of 30 subjects. An effect on sound quality from the noise suppression equivalent to about 3-4 dB is required to be statistically significant for a single subject. A corresponding effect of 3-6 dB is required for speech recognition (one-sided test). The magnitude of difference that occurred in the present study for sound quality was sufficient to show significant differences for sound quality within individuals, but this was not the case for speech recognition.

Closed-set word tests can be implemented with or without trial-by-trial visual feedback. Feedback is considered to increase subject motivation yet its influence on performance is unknown. The aim of this study was to compare performance on the Four Alternative Auditory Feature (FAAF) test with and without visual feedback over a 24-week period following fitting of a hearing aid. A total of 32 elderly subjects were recruited as new users and fitted monaurally with the same model of linear, programmable hearing aid that provided in excess of 20 dB insertion gain at 2-4 kHz. Half of the subjects were provided with visual feedback. In these subjects, mean performance increased by 5% across the study period. The improvement in performance over time was statistically significant on analysis of variance (p < 0.05). Mean performance did not increase in the remaining subjects who were not provided with feedback. If closed-set word tests are to be used with visual feedback to measure changes over time, the potentially confounding effects of practice must be controlled carefully. Alternatively, omitting feedback leads to simpler experimental designs.

The time course of changes in perceived sound quality after hearing instrument fitting has not been studied systematically It is possible, for example, that patients may object to additional high frequency gain when fitted, but not after a period of auditory acclimatisation. The aim of this study was to utilise sound quality judgements to compare two frequency responses in new users at 4-week intervals over a 24-week post-fitting period. The null hypothesis was that there would be no change in sound quality judgements over time. A total of 16 elderly subjects were fitted monaurally with the same model of linear, programmable hearing instrument. This was set to a standard response that provided 26-29 dB of real-ear insertion gain at 2000 4000 Hz. This program was worn by the subjects for the duration of the study. All subjects reported greater than four hours of daily use. The alternative response which was used in a paired comparison paradigm, provided a mean gain reduction of 3, 8, 13, and 16 dB at 2000, 3000, 4000 and 6000 Hz, respectively. Subjects compared the standard and the alternative responses for sound quality along dimensions of comfort, clarity, and overall preference while listening to running speech presented in quiet, steady noise, and speech babble. At the time of fitting there was a small preference for the standard response when judging clarity, but the alternative response was preferred for comfort and preferred overall. Repeated-measures analysis of variance (ANOVA) for each quality dimension did not reveal any statistically significant change over time. It is concluded that this pattern of preference is unaffected by acclimatisation to amplification, at least over the initial 24 weeks of instrument use.

Evidence for the existence of auditory acclimatization is mixed, and the implications for clinical practice are unclear. The aim of this study was to seek evidence of perceived changes in performance over a 24-week post-fitting period. Thirty-two new, elderly subjects were recruited and fitted monaurally with the same model of linear, programmable hearing aid that provided in excess of 20-dB insertion gain at 2000-4000 Hz. The Glasgow Hearing Aid Benefit Profile (GHABP) was used to measure self-reported changes over time. The questions concerning benefit and satisfaction were modified to produce two versions: half of the subjects reported changes relative to the time of fitting, while the remainder reported changes relative to the previous occasion on which they completed the GHABP (3 weeks earlier). Subjects reported using hearing aids in excess of 90% of the time when in listening situations that cause difficulty. The median residual disability measure from the GHABP remained low (10-20%) over the duration of the study. The median scores for additional benefit and satisfaction showed a small but statistically significant improvement over the first 3 months of hearing aid use but only for the subjects who referenced this to their perceived performance 3 weeks earlier. The limited evidence for self-reported improvements in benefit and satisfaction over time reported to date must be tempered by the possibility of response bias arising from the method used to measure changes over time.

Speech recognition performance and self-reported benefit from linear analogue and advanced (digital) hearing aids were compared in 100 first-time hearing aid users with mild-to-moderate sensorineural hearing loss fitted monaurally with a behind-the-ear (BTE) hearing aid in a single-blind randomized crossover trial. Subjects used each aid for 5 weeks in turn, with aid order balanced across subjects. Three alternative models of digital hearing aid were assigned to subjects according to a balanced design. Aid type was disguised to keep subjects blind within practical limitations. Aided speech recognition performance in noise was measured at speech levels of 65 and 75dB at a speech-to-noise ratio (SNR) of +2dB for closed sets of single words. Self-rated benefit was measured using the Abbreviated Profile of Hearing Aid Benefit (APHAB) and the Glasgow Hearing Aid Benefit Profile (GHABP). Quality of life, hearing aid use and user preferences were also assessed. Speech recognition scores with the digital aids were significantly better at 75dB than with the analogue aids Self-reported benefit (APHAB, GHABP) and improvement in quality of life were generally not significantly different between analogue and digital aids, although aversiveness measured with the APHAB was significantly lower with digital aids, and satisfaction measured with the GHABP was greater. The digital aids were preferred significantly more often than the analogue aids, with 61 subjects choosing their digital aid, 26 choosing the analogue aid, and nine being equivocal. Overall, this study shows advantages for advanced digital over simple linear analogue aids in terms of both objective and subjective outcomes, although average differences are not large.

Auditory brainstem responses (ABRs) using clicks enable global objective estimation of hearing threshold. Recently, it has been suggested that a chirp stimulus may produce a synchronous response from a larger portion of the basilar membrane than a click, and that a chirp will produce a greater amplitude response than a click at the same sensation level. Various workers have modified the stimulus to achieve frequency specificity (e.g. using tone-bursts). The present investigation used band-limited chirp stimuli having the same frequency-delay characteristics as the chirp mentioned above that compensate for frequency-dependent cochlear delays. The intention was to generate highly synchronized neural responses across parts of the nerve fibre array. Stimuli were presented at sensation levels between 10 and 50 dB to 10 adult subjects. Wave V was consistently identifiable even for low-frequency stimuli. Wave V amplitude increased and latency decreased as stimulus frequency increased. The latency decrease is consistent with high-frequency responses arising from basal regions of the cochlea. ABR thresholds were defined by objective estimation and visual inspection. Average ABR thresholds were 16 dB higher than behavioural thresholds for high-frequency chirps (3000-6000 Hz), increasing to 25 dB for low-frequency chirps (375-750 Hz). These ABR thresholds are closer to behavioural thresholds and have a smaller variance than reported for tone-burst stimuli without masking. However, they are not as close as those reported for tone-bursts in notched noise. The disadvantage of the band-limited chirps is that they have a wider spectral spread than tone-bursts and hence may elicit a response from unwanted frequency regions of the basilar membrane.

The educational settings of 42 implanted profoundly deaf children 3 years after implantation were compared with the respective settings of 635 age-matched severely deaf and 511 profoundly deaf children with hearing aids. All implanted children received their implants before beginning school. The results revealed that 3 years after implantation. 38% (16 children) of the implanted profoundly deaf children attended mainstream schools, whereas 57% (24 children) were in a unit, or special class, in a mainstream school, and 5% (two children) were in schools for the deaf. With regard to the age-matched profoundly deaf children with hearing aids, 12% (63 children) attended mainstream schools, whereas 55% (281 children) were in a unit of a mainstream school, and 33% (167 children) were in schools for the deaf. In the group of age-matched severely deaf children, 38% (239 children) attended mainstream schools, whereas 51% (326 children) were in a unit of a mainstream school, and 11% (70 children) were in schools for the deaf. Statistical analysis revealed a highly significant difference between the educational placement of implanted children and hearing-aided profoundly deaf children (p<0.00001), whereas there was no statistically significant difference between implanted children and hearing-aided severely deaf children. In conclusion, implanted profoundly deaf children who have received their implants before beginning school have the same profile of educational placement as aided severely deaf children rather than aided profoundly deaf children of the same age in the UK. This is likely to have significant implications for the future management of profoundly deaf children and to influence future planning of educational support services.